Rhythmic alpha discharges in the EEGs of the newborn.

Electroclinical features of neonatal rhythmic alpha discharges were described on the basis of polygraphic recordings from 37 newborns with seizures. The main presumptive etiological factors were perinatal hypoxia, hypocalcemia, purulent meningitis and intracranial hemorrhage. Apneic seizures were most often associated with temporal alpha discharges, whereas clonic seizures were mainly associated with central ones. Sleep cycles were abolished in half of the infants, but in those with sleep cycles, clinical seizures occurred most frequently during active sleep. Alpha discharges occurring during quiet sleep were not associated with clinical fits. The neonates who suffered from perinatal hypoxia and/or intracranial birth injury all developed abnormally, whereas those with hypocalcemia showed the most favorable outcome. Those with other etiologies demonstrated an intermediate prognosis between the two.